Plot3D[Min[Max[0,Abs[Zeta[x+y]]],9],{x,-5,9},{y,3/4,30},AxesNone,BackgroundBlack,BoxedFalse,BoxRatios{1.,1.,0.8},ColorFunctionFunction[{x,y},Hue[1/2+ArcTan[5Arg[Zeta[x+y]]]/π]],ColorFunctionScalingFalse,ExclusionsNone,ImageSizeLarge,Mesh80,MeshStyleBlack,ViewPoint{0.15,-2.,1.1}]